/*******************************************************************************
 * Copyright (C) 2023 DFKI GmbH (https://www.dfki.de/en/web)
 * 
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * 
 * SPDX-License-Identifier: MIT
 ******************************************************************************/
package org.eclipse.digitaltwin.basyx.aasregistry.service.storage.mongodb;

public class SimpleVarNameProvider {
	
	private String currentVariable = "a";

	public String next() {
		String current = currentVariable;
		incrementVariableName();
		return current;
	}

	private void incrementVariableName() {
		int lastPos = currentVariable.length() - 1;
		char lastChar = currentVariable.charAt(lastPos);
		if (lastChar == 'z') {
			currentVariable = currentVariable + "a";
		} else {
			char nextChar = (char) (lastChar + 1);
			currentVariable = currentVariable.substring(0, lastPos) + nextChar;
		}
	}
}
